/* eslint-disable @typescript-eslint/no-loss-of-precision */
// WGS-84：是国际标准，GPS坐标(Google Earth使用、或者GPS模块)
// GCJ-02：中国坐标偏移标准，Google Map、高德、腾讯使用
// BD-09：百度坐标偏移标准，Baidu Map使用

let gpsConvert = {
	PI: 3.14159265358979324,
	x_pi: (3.14159265358979324 * 3000.0) / 180.0,
	delta(lat: number, lon: number) {
		let a = 6378245.0; //  a: 卫星椭球坐标投影到平面地图坐标系的投影因子。
		let ee = 0.00669342162296594323; //  ee: 椭球的偏心率。
		let dLat = this.transformLat(lon - 105.0, lat - 35.0);
		let dLon = this.transformLon(lon - 105.0, lat - 35.0);
		let radLat = (lat / 180.0) * this.PI;
		let magic = Math.sin(radLat);
		magic = 1 - ee * magic * magic;
		let sqrtMagic = Math.sqrt(magic);
		dLat = (dLat * 180.0) / (((a * (1 - ee)) / (magic * sqrtMagic)) * this.PI);
		dLon = (dLon * 180.0) / ((a / sqrtMagic) * Math.cos(radLat) * this.PI);
		return { lat: dLat, lon: dLon };
	},

	//WGS-84 to GCJ-02
	gcj_encrypt(wgsLat: number, wgsLon: number) {
		if (this.outOfChina(wgsLat, wgsLon)) return { lat: wgsLat, lon: wgsLon };

		let d = this.delta(wgsLat, wgsLon);
		return { lat: Number(wgsLat) + Number(d.lat), lon: Number(wgsLon) + Number(d.lon) };
	},
	//GCJ-02 to WGS-84
	gcj_decrypt(gcjLat: number, gcjLon: number): { lat: number; lon: number } {
		if (this.outOfChina(gcjLat, gcjLon)) return { lat: gcjLat, lon: gcjLon };

		let d = this.delta(gcjLat, gcjLon);
		return { lat: Number(gcjLat) - Number(d.lat), lon: Number(gcjLon) - Number(d.lon) };
	},
	//GCJ-02 to WGS-84 exactly
	gcj_decrypt_exact(gcjLat: number, gcjLon: number) {
		let initDelta = 0.01;
		let threshold = 0.000000001;
		let dLat = initDelta,
			dLon = initDelta;
		let mLat = gcjLat - dLat,
			mLon = gcjLon - dLon;
		let pLat = gcjLat + dLat,
			pLon = gcjLon + dLon;
		let wgsLat,
			wgsLon,
			i = 0;
		while (1) {
			wgsLat = (mLat + pLat) / 2;
			wgsLon = (mLon + pLon) / 2;
			let tmp = this.gcj_encrypt(wgsLat, wgsLon);
			dLat = tmp.lat - gcjLat;
			dLon = tmp.lon - gcjLon;
			if (Math.abs(dLat) < threshold && Math.abs(dLon) < threshold) break;

			if (dLat > 0) pLat = wgsLat;
			else mLat = wgsLat;
			if (dLon > 0) pLon = wgsLon;
			else mLon = wgsLon;

			if (++i > 10000) break;
		}
		//console.log(i);
		return { lat: wgsLat, lon: wgsLon };
	},
	//GCJ-02 to BD-09
	bd_encrypt(gcjLat: number, gcjLon: number) {
		if (this.outOfChina(gcjLat, gcjLon)) return { lat: gcjLat, lon: gcjLon };

		let x = gcjLon,
			y = gcjLat;
		let z = Math.sqrt(x * x + y * y) + 0.00002 * Math.sin(y * this.x_pi);
		let theta = Math.atan2(y, x) + 0.000003 * Math.cos(x * this.x_pi);
		let bdLon = z * Math.cos(theta) + 0.0065;
		let bdLat = z * Math.sin(theta) + 0.006;
		return { lat: bdLat, lon: bdLon };
	},
	//BD-09 to GCJ-02
	bd_decrypt(bdLat: number, bdLon: number) {
		let x = bdLon - 0.0065,
			y = bdLat - 0.006;
		let z = Math.sqrt(x * x + y * y) - 0.00002 * Math.sin(y * this.x_pi);
		let theta = Math.atan2(y, x) - 0.000003 * Math.cos(x * this.x_pi);
		let gcjLon = z * Math.cos(theta);
		let gcjLat = z * Math.sin(theta);
		return { lat: gcjLat, lon: gcjLon };
	},
	//WGS-84 to Web mercator
	//mercatorLat -> y mercatorLon -> x
	mercator_encrypt(wgsLat: number, wgsLon: number) {
		let x = (wgsLon * 20037508.34) / 180;
		let y = Math.log(Math.tan(((90 + wgsLat) * this.PI) / 360)) / (this.PI / 180);
		y = (y * 20037508.34) / 180;
		return { lat: y, lon: x };
	},
	// Web mercator to WGS-84
	// mercatorLat -> y mercatorLon -> x
	mercator_decrypt(mercatorLat: number, mercatorLon: number) {
		let x = (mercatorLon / 20037508.34) * 180;
		let y = (mercatorLat / 20037508.34) * 180;
		y = (180 / this.PI) * (2 * Math.atan(Math.exp((y * this.PI) / 180)) - this.PI / 2);
		return { lat: y, lon: x };
	},
	// two point's distance
	distance(latA: number, lonA: number, latB: number, lonB: number) {
		let earthR = 6371000;
		let x = Math.cos((latA * this.PI) / 180) * Math.cos((latB * this.PI) / 180) * Math.cos(((lonA - lonB) * this.PI) / 180);
		let y = Math.sin((latA * this.PI) / 180) * Math.sin((latB * this.PI) / 180);
		let s = x + y;
		if (s > 1) s = 1;
		if (s < -1) s = -1;
		let alpha = Math.acos(s);
		let distance = alpha * earthR;
		return distance;
	},
	outOfChina: function (lat: number, lon: number) {
		if (lon < 72.004 || lon > 137.8347) return true;
		if (lat < 0.8293 || lat > 55.8271) return true;
		return false;
	},
	transformLat(x: number, y: number) {
		let ret = -100.0 + 2.0 * x + 3.0 * y + 0.2 * y * y + 0.1 * x * y + 0.2 * Math.sqrt(Math.abs(x));
		ret += ((20.0 * Math.sin(6.0 * x * this.PI) + 20.0 * Math.sin(2.0 * x * this.PI)) * 2.0) / 3.0;
		ret += ((20.0 * Math.sin(y * this.PI) + 40.0 * Math.sin((y / 3.0) * this.PI)) * 2.0) / 3.0;
		ret += ((160.0 * Math.sin((y / 12.0) * this.PI) + 320 * Math.sin((y * this.PI) / 30.0)) * 2.0) / 3.0;
		return ret;
	},
	transformLon(x: number, y: number) {
		let ret = 300.0 + x + 2.0 * y + 0.1 * x * x + 0.1 * x * y + 0.1 * Math.sqrt(Math.abs(x));
		ret += ((20.0 * Math.sin(6.0 * x * this.PI) + 20.0 * Math.sin(2.0 * x * this.PI)) * 2.0) / 3.0;
		ret += ((20.0 * Math.sin(x * this.PI) + 40.0 * Math.sin((x / 3.0) * this.PI)) * 2.0) / 3.0;
		ret += ((150.0 * Math.sin((x / 12.0) * this.PI) + 300.0 * Math.sin((x / 30.0) * this.PI)) * 2.0) / 3.0;
		return ret;
	}
};

export default gpsConvert;
